The remainder, from NY 384 to Lewiston, is known as the Niagara Expressway and is maintained by the New York State Department of Transportation (NYSDOT).

The entire route was built as part of the New York State Thruway in the late 1950s and early 1960s and was completed in 1964.

I-190 heads west into Buffalo, passing the former location of the City Line toll barrier ahead of an interchange with South Ogden Street (exit 1).

Within the downtown area, I-190 passes between KeyBank Center and Sahlen Field near an interchange with NY 5 (exit 7) on the shores of Lake Erie.

The two routes then meet I-290 and NY 266 a second time prior to crossing the Niagara River on the South Grand Island Bridge.

In Lewiston, the expressway meets NY 31 at exit 24 southwest of the large Robert Moses Niagara Power Plant reservoir.

Construction on two segments of the highway—from South Ogden Street to Porter Avenue in downtown Buffalo and from Beaver Island Parkway to West River Road on Grand Island—began in 1953.

[7] On July 30, 1959, the thruway was opened from the Tri-Level Interchange at I-90 to Porter Avenue and from Sheridan Drive to the southern Grand Island bridge.

[14] On October 30, 2006, the NYSTA voted to both begin the process of returning maintenance of I-84 to NYSDOT and to remove the tolls on I-190 in Buffalo.